A particle of charge -q and mass m moves in a circle of radius r around an infinitely long line charge of linear charge density +$\mathrm{\lambda }$. Then its time period is $\left(\text{ where }\mathrm{k}=\frac{1}{4{\mathrm{\pi \epsilon }}_0}\right)$

• A

  $\mathrm{T}=2\mathrm{\pi r}\sqrt{\frac{\mathrm{m}}{2\mathrm{k\lambda q}}}$

• B

  ${\mathrm{T}}^2=\frac{4{\mathrm{\pi }}^2\mathrm{m}}{2\mathrm{k\lambda q}}$

• C

  $\mathrm{T}=\frac{1}{2\mathrm{\pi r}}\sqrt{\frac{2\mathrm{k\lambda q}}{\mathrm{m}}}$

• D

  $\mathrm{T}=\frac{1}{2\mathrm{\pi r}}\sqrt{\frac{\mathrm{m}}{2\mathrm{k\lambda q}}}$